Onset of double-diffusive convection in near-critical gas mixtures
Onset of double-diffusive convection in near-critical gas mixtures
复制标题
近临界气体混合物中双扩散对流的开始
DOI：
10.1103/physreve.99.033112
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发表时间：
2019
影响因子：
2.4
通讯作者：
Zhang Xin-Rong
中科院分区：
文献类型：
--
作者：
Hu Zhan-Chao;Davis Stephen H.;Zhang Xin-Rong
在热力学临界点附近，二元流体的物理性质随着小的温度和浓度差异而表现出很大的变化，这里报告了其对双扩散对流开始的影响。垂直对称性被破坏，出现不规则的穿透不稳定，并且分别在指法状态和振荡状态中识别出猫眼图案。定义了一个新参数，该参数指示物理特性的变化如何影响流场。通过数值模拟可以看出，具有恒定物理性质的 Boussinesq 近似的适用性有限，而具有可变性质和密度的 Boussinesq 方程将描述所有看到的特征。这个结论是基于与完全可压缩的可变属性系统的比较。
Near the thermodynamic critical point, the physical properties of binary fluids exhibit large variations in response to small temperature and concentration differences, whose effects on the onset of double-diffusive convection are reported here. The vertical symmetry is broken, irregular penetrative instability occurs, and cat's eye patterns are identified in the fingering regime and oscillatory regime, respectively. A new parameteris defined which indicates how the variations of physical properties influence flow fields. It is seen through numerical simulations that the Boussinesq approximation with constant physical properties has limited applicability, and that the Boussinesq equations with variable properties and density will describe all features seen. This conclusion is based on comparisons with the fully compressible, variable-property system.